Distillation of crude petroleum



Patented Apr. 27, 1926 UNITED. STATES PATENT OFFICE.

EDGAR MILTON CLARK, OF YORK, N. Y., ASSIGNOR 1'0 STANDARD DEVELOEMENT COMPANY, A CORPORATION OF DELAWARE.

DISTILLATION OF CRUDE PETROLEUM.

No Drawing. Application filed July 8,

To all whom it may concern:

Be it known that I, EDGAR M. CLARK, a citizen of the United States, residing at New York, in thecounty of New York and 5 State of New York, have invented a new and useful Improvement in Distillation of Crude Petroleum, of which the following is a speci fication.

My present invention relates to the distillation of crude petroleum and will be fully understood from the following specification. In the distillation of crude petroleum as heretofore practiced, it has been the custom to continue the distillation process until there is obtained a dry residue in the form of petroleum coke, the main use of this prodnot being as a fuel.. By practicing the distillation in this manner, there is in general obtained a high yield of valuable products of crude oil, with the resultant disadvantage. however, that the coke residue is worth little more than a good grade of coal (and may even be worth much less if its sulphur content is high), while the labor involved in removing the coke from the stills at .the end of the run. coupled with the heavy depreciation of the apparatus, involves a considerable expense.

In accordance with the present invention I propose to practice a method of distillation by which there is obtained a yield of valuable products substantially the same as that obtained in carrying the distillation to coke, but without the expense of the latter method.

For the practice of my process, I prefer to employ a. series of continuous stills Wl'llCll may e of the usual type commonly employed in re distilling petroleum products. In this common arrangement of apparatus several stills are placed side by side, each still being equipped with its individual furnace, va r lines and condensers, the several stills being connected by overflow pipes so that the oil to be treated maybe introduced into the first still of the, series and thence find its way b means of the overflow pi s successively through the remaining sti ls,

. a the undistilled residue being withdrawn from the last still. The necessary gravity through the several stills.

1919. Serial no. 308,645.

'common methods is equally well adapted to the practice of my present process. In addition to the coal-burning furnace or other means for externally heating each still, I emplo stills of the type in which provision is ma e for introducing superheated steam (or other chemically inert gas) directly into the oil body under distillation within the still. This is likewise common practice in continuous distillation operations and will be well understood by those skilled in the art.

In the practice of the present process, the

above described apparatus, which may be identified slmply as a string of continuous stills arranged for distillation by fire and steam, is operated as follows:

The crude oil, for example, American midcontinent crude, is fed into the first still of the series and caused to flow progressively Each still will be fired at such a rate as to take oil substantially the same volume of distillate, this effect being obtainable by maintaining higher temperatures in the several stills in the direction of flow of the oil and by the proper adjustment of the volume of steam injected into the oil during distillation. The percenta e of distillate taken off from each still shoul be so regulated that the residue removed from the last still will be a. pitch of very high melting point. For example, I have found it possible to operate the process described upon mid-continent crude petroleum, removing from the last still continuous- 1y a pitch representing. 4% by volume (4 by weight) of the crude oil, and having the following specifications:

S ecific avit 1. 214 4 ash Z 407 F. Melting point (ball and ring test)- 320 F. Hexane soluble 25% The percentage of total volatile matter and of fixed carbon inthe foregoing specifications is obtained by the standard method of heating a small sample of the pitch in a spoon over an open flame for seven minutes,

thus reducing it substantially to coke.

The high melting point pitch thus produced and represented by way of example in the foregoinw specifications, upon being removed from tie still may be run into open pits where it cools and solidifies, being then broken up into lumps of convenient size for handling, or alternatively, the pitch may be run to a cooling and granulating apparatus of any desired form, to be there reduced to the formof a granular solid.

The solid .pitchthus produced, either in lumps of sizeconvenient for handling, or in a granular condition, forms an excellent fuel, free from ash, and capable of being burned either in admixture with coal, as a powdered fuel,or as a liquid fuel, in open pans replacing the ordinary grate bars.

It will be seen that the foregoing process therefore produces in a continuous manner, as a residue of distillation, a fuel product substantially the same in percentage as the coke heretofore produced by carrying the distillation to dryness. By reason of the fact that the process ma be operated contmuously as described, the capacity of the distilling equipment is very greatly increased, and the difficulties and expense and deterioration in quality of the distillates due to excessive cracking 1n the latter stages of the run with fire alone involved in the ordinary method of distilling to dryness is avoided.

I am aware that crude petroleum has heretofore been distilled both by the batch and continuous method for the production of residual pitches, but, so far as I am aware, such pitches have either been of the grade of asphalt, .or even of lower melting point and no attempt has been made to obtain by this species of distillation a yield of distillate of a quality substantially the same as and of a quality better than that now obtained by distilling to-dryness.

While I have in the foregoing described inconsiderable detail. a preferredprocess in accordance with my invention, it will be understood that this is illustrative only, and that the invention is not limited to the ex 'alct' procedure described, except in' so far as such limitations form a part of the accompanyingcla-ims, in. which .it is my intention to claim all novelty inherent in the invention as broadly as is permissible in view of the prior art.

ing temperature until there is produced a residual fuel pitch in quantity substantially the same as the quantity of coke which may be produced by distilling the same oil to dryness by fire alone, and removing said fuel pitch from the still while it is in liquid e0 condition.

2. The method of distilling crude petroleum for obtaining a maximum yield of substantially uncracked distillate therefrom which consists in carrying on the distillation of a body of said crude petroleum with the aid of injected steam and below cracking temperature until there is produced a residual fuel pitch in quantity substantially the same as the quantity'of coke which may be produced by distilling the same oil with fire alone to dryness, removing said fuel pitch from the still while it is in liquid condition, and cooling, solidifying and subdividing the pitch to'form a solid fuel made up of discrete particles.

3. The method of distilling crude petroleum which consists in conducting the distillatory operation in a series of continuous stills, through which the petroleum passes in succession, and with the aid of in ected steam and below crackin temperature in at least the last still 0 the series, carrying the distillation to the point where the residue constitutes a fuel pitch in quantity substantially the same as that of the coke which would be obtained were distillation carried to dryness by fire alone, and removing the residue from the last still while it is in a liquid condition.

4. The method of distilling crude petroleum which consists in conducting the distillatory operation in a series of continuous stills, through which the petroleum passes in succession and with the aid of injected steam and below cracking temperature in at least the last still of the series, carrying the distillation to the point where the residue constitutes a fuel pitch in quantity substantially the same as that of the coke which would be obtained were distillation carried to dryness with fire alone, removing the residue from the last still while it is in liquid condition, and cooling, solidifying and subdividing. the pitch to form a solid fuel-made up of discrete particles.

5. The method of distilling crude petroleum which consists in carrying on the disti1 lation thereof with the aid of injected steam until there is produced a residual pitch having a melting point of at least about 320 F., and removing said pitch from the still while it is in liquid condition.

6. The method of distilling crude petroleum of mid-continent type which consists in carrying on the distillation with the aid of injected steam until there is ploduced a residual pitch in quantity amounting to 10 about 4% by volume of the original oil, and removing said pitch from the still While it is in liquid condition.

EDGAR MILTONY- CLARK. 

